Novelty yarns are conventionally produced on specialized machinery, such as a novelty twister, wherein several separate pairs of feed rolls are employed for feeding two or more yarns together at different rates in such a manner that certain of the yarns serve as "effect" yarns and become wrapped about other yarns to form novelty effects such as knops, loops, curls, etc. The thus formed yarn is usually twisted again in a subsequent twisting operation while a fine binder yarn is applied to hold the effect yarn or yarns in place.
By way of example, a conventional method of producing a loop yarn on a novelty twister involves delivering an effect yarn from a pair of delivery rolls in an overfed condition between a pair of advancing base yarns so that the overfed effect yarn forms circular loops which are trapped between the two base yarns. In a subsequent twisting operation a binder yarn is applied to the yarn to stabilize the yarn and hold the loops in place.
The relatively high cost of the specialized novelty twisters required in conventional novelty yarn methods and the relatively slow operating speed and limited versatility thereof significantly increase the production cost of novelty yarns produced by these methods as compared to conventional yarns and often cause the novelty yarns to be of limited availability.
Allen U.S. Pat. No. 3,945,189 discloses a method for producing a novelty yarn without using a novelty twister. This method uses a conventional spinning frame to produce a knop yarn, i.e. a yarn having prominent bunches of effect yarn arranged at irregular intervals along its length. In accordance with this method an effect yarn is supplied to a foundation yarn advancing from the drafting zone to the spindle of a spinning frame and the tension of the effect yarn is adjusted so that the effect yarn oscillates with respect to the advancing foundation yarn and forms irregular knops on the foundation yarn made up of layers of the effect yarn.
The present invention, like the method of the Allen patent, is concerned with producing a novelty yarn on conventional textile equipment and without using a novelty twister. However, the present invention is concerned with producing a yarn of a distinctly different type and appearance from that of the Allen patent. More particularly, the present invention is concerned with producing a unique and appealing loop-type yarn characterized by having effect loops of random size distributed at random locations along the yarn. The Allen patent, on the other hand, is not concerned with a yarn having loops thereon, but rather is concerned solely with producing a novelty yarn having knops or elongated knops thereon.
A publication of the International Wool Secretariat, "Technical Information Bulletin No. 17, Fancy Yarns" January, 1975, gives a further and considerably more detailed description of the method and resulting knop yarns described in the Allen patent. This publication also discloses that loop yarns and boucle yarns can also be produced by methods related to the knop yarn method. As described therein, the knop yarn produced as in the Allen patent is used as a starting material and subjected to subsequent processing operations in order to produce loop or boucle type yarns.
The novelty yarn of the present invention differs fundamentally from the loop or boucle yarns described in this publication. As will become readily apparent from the description which follows, the method by which the novelty yarn of the present invention is produced, as well as the resulting yarn, differ in several very significant respects from the methods and yarns disclosed in the above noted prior art.